Several plants with Cycas-like leaves (after Thomas: The
evolution of plants and flowers, 1981).
There were two groups with Cycas-like leaves: the real cycads
and the Bennettitales.
The last (now extinct) group has no English name. The plants of this
group had
already flowers. It has been thought that the modern flowering plants derived
from these plants, but it has proven not to be true. It is difficult to
distinguish
between cycads and Bennettitales. Microscopic preparations of the cuticle
are
needed for that. |
Williamsonia: a flower of a Bennettitales plant.
Yorkshire, Middle Jurassic. Width of the photo 12 cm. |